1. Field of the Invention
The present invention relates to a method, an arrangement, and a temperature sensor in order to make a determination of the interior temperature of a vehicle, taking into consideration changing heat transmission resistance of a control element surface to the surrounding air flow.
2. Description of the Background Art
To automatically regulate the interior temperature in a motor vehicle it is necessary to know the actual interior temperature at a particular time point. As a rule, a control value is determined, which reflects the deviation of the actual interior temperature from the desired interior temperature. The control value serves to regulate the difference. Such a method is described in DE 40 24 431 A1, which is incorporated herein by reference.
In DE 198 29 143 C1, which is incorporated herein by reference, a further method for changing the interior temperature of a vehicle is disclosed. To compensate for changes in the actual value of the interior temperature due to exterior influences, for example low exterior temperature, an interior temperature-sensing element as well as an exterior sensor are provided. The interior temperature-sensing element is located in a control unit.
DE 197 28 803 C1, which is incorporated herein by reference, discloses an arrangement for measuring and/or regulating temperature with a housing, inside of which is a temperature-sensing element for measuring the interior temperature outside of the housing, whereby one or several heat sources are present inside and/or on the housing. Additionally, at least one auxiliary temperature-sensing element is provided inside the housing at an area where the temperature is more intensely influenced by the heat flow from the heat source than is the temperature at the temperature-sensing element.
A disadvantage of the solution just described is the big deviation of the measured temperature signals from the actual interior temperature due to the large amount of interferences with the sensor as well as the great inertness of the sensor, which detects changes in the interior temperature with a time delay and smoothed. Therefore, considerable effort to correct the temperature signals is required.
From DE 100 16 419 C2, which is incorporated herein by reference, a device for indirectly recording incident sun radiation in the interior of a vehicle is known. The photo sensor used is attached to a housing in such a way that it is not exposed directly to incident sun radiation and, therefore, only measures the radiation of the sun that is reflected and/or transmitted into the interior of the vehicle.
Presently, measuring methods are being developed, which measure the interior temperature directly on the surface of a control element without forced air circulation using a NTC (resistor with a negative temperature coefficient), e.g., a NTC thermistor. The unreliability of this measuring method is a result of the varying air circulation on the surface of the control element, which greatly relativizes the measurement values at the NTC, even when taking self-heating and the influence of the sun into consideration.
From DE 100 49 979 C2, which is incorporated herein by reference, a device for determining the temperature in the interior of a vehicle is known, whereby the temperature-sensing element is arranged behind a wall adjoining the interior. A heat-conducting element is provided to record the air temperature of the interior within the area close to its walls. The heat-conducting element is in heat conductivity contact with a temperature-sensing element and is attached to and/or close to the wall or in an opening in the wall. With this device, interference from partial sun radiation on the sensor housing is recorded and corrected accordingly.